Personal hygiene remains the major method of preventing and treating bacterially induced periodontal diseases. Daily flossing and brushing are the primary means of limiting the colonization of dental plaque by periodontopathic bacteria. However, this regimen fails in a large segment of the population. Simpler and more effective methods of plaque removal are needed. We believe that low levels of sonic energy can effectively disrupt plaque deposits and prevent buildup of the microbially complex plaque associated with periodontitis. Our device applies such energy via the bristles of a toothbrush. Preliminary trials have shown that the device dislodges plaque from dog and human teeth, and may damage or destroy bacterial appendages essential for microbial adherence and/or motility. This battery powered device is inherently inexpensive to manufacture, and has the potential for being readily affordable and usable by the general public. If the device fulfills its potential it could become a major mode of home dental care, complementing or even replacing the conventional toothbrush. We plan to develop our current prototype so that it can be tested clinically. We will develop acoustic measurement techniques, and use them to make design improvements to optimize the cleaning action and bacterial disruption. Limited experiments using mongrel dogs will help determine the optimum design. In addition, preliminary histopathologic studies on possible adverse effects of prolonged use of the brush on oral tissues will be conducted on the dogs.